Determine whether compounds with mutagenic activity can be dedected in body fluids of defined human populations. Standard techniques will be developed to permit detection of various classes of mutagens/carcinogens in human urine samples using mutagenesis tests with various microbial strains which can be used as indicators of mutagenic activity. Minimum quantities of known mutagens will be added to urine and carried through the extraction procedure and tested at each step to determine mutagenic activity. After the development of a reliable and sensitive protocol using the above approach, the second phase of the study will consist of extracting and testing a series of human urines from defined populations. Other body fluids and tissues including blood and feces can be used with development of methodology and testing analogous to that described for the urine samples.